What is a limiter? And is there a difference between a compressor and limiter? Both are good questions and are something I get asked quite often. And they are questions I often wonder myself.
 
The simple answer is that a compressor and limiter are exactly the same thing. Both a limiter and compressor limit the volume of a signal when it exceeds the user-defined threshold. There is a simple rule, and that is when using a ratio of 10:1 or higher, then it is usually considered to be a limiter and anything under is a compressor. However, as with anything in the mastering world, there are a huge number of exceptions. In fact, there are too many to go into detail in this article, but I will address sum (ahem), some of them.
 
Audio limiting as described by Wikipedia is: “Any process by which a specified characteristic (usually amplitude) of the output of a device is prevented from exceeding a predetermined value.” That predetermined value is the threshold set by the user.
 
Typically in a mastering setup, limiting is used to increase the overall volume of a track. As I talked about above, the individual peaks of a track are brought down or squashed whilst the overall volume of the track is increased. In comes the loudness wars; I won’t get into that here, but essentially, most modern music is squashed using a limiter and the volume is increased making the track very loud. There is a tradeoff though; the natural dynamics of a track are lost. The natural ebb and flow is gone and the song tends to be straight ahead and loses a sonic quality, but it’s loud.
 
In mastering we use a limiter to decrease the volume of the loud parts of a song (let’s say the chorus) and increase the volume of the quieter (the verse) parts by pulling the threshold down and increasing the ratio and make-up gain on the compressor (limiter).
 
Make sense? Let me know your thoughts.
 
“The brain is an instrument that measures quantum information. Consciousness constructs the material world out of that measured information.” Deepak Chopra